Electronic instrument having a magnetic sensor

ABSTRACT

Arranging a magnetic sensor in a position within 2 −1/2  of the radius from the center of a component in a circular shape assuming magnetism, and correcting deflection by deflection amount correcting circuit of an output from the magnetic sensor in accordance with the relative position between the magnetic sensor and the component.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an electronic instrument havinga magnetic sensor, particularly to an electronic azimuth indicatorincluding a part having magnetic susceptibility that affects a magneticsensor, or to a various kinds of electronic instruments provided withsuch an electronic azimuth indicator.

[0003] 2. Description of the Prior Art

[0004] As an example of such an electronic instrument that has beenconventionally used, there is a wristwatch provided with an electronicazimuth indicator. Such a wristwatch with an electronic azimuthindicator has a problem that, when a magnetic sensor is arranged in thevicinity of a part that is susceptible to magnetization or a partassuming magnetism, accurate detection of a direction is difficultbecause such a part adversely affect the magnetic sensor.

[0005] To describe it more concretely, geomagnetism can be generallyregarded as an even magnetic field. When a spherical magnetic body isarranged in such an even magnetic field, the magnetic field is distortedas shown in FIG. 14. FIG. 14 shows a state of the magnetic field inwhich a spherical magnetic body is arranged in an even magnetic field.As can be seen from the figure, the direction of the magnetic field isdeflected to the direction of a spherical magnetic body 19 as shown by amagnetic field 9a in the vicinity of the spherical magnetic body 19.Such a phenomenon is observed when an article assuming magnetism (amagnetic body) is placed within the magnetic field.

[0006] In addition, an electronic instrument such as a wristwatch withan electronic azimuth indicator uses a magnetic body such as a batteryand a capacitor, and particularly there are a lot of button batteriesthat use 304 stainless steel processed to have a circular shape.Although it is generally considered that such 304 stainless steel doesnot have magnetism, when the stainless steel elongates due to diecutting or bending, magnetism may occur in the direction of theelongation.

[0007] For example, as shown in FIG. 15, if the entire outerconfiguration of the circular stainless steel is processed to elongatein the circumference direction, the elongation occurs from the inside to-the outside with respect to the outer configuration as shown by arrows.Magnetism is observed with the direction of the elongation as an axis.

[0008] Therefore, when it is necessary to arrange a magnetic sensor inthe vicinity of a magnetic body or a button battery, there is apossibility that detection of magnetic field components is adverselyaffected due to the above -mentioned effects.

[0009] As prior art for solving this problem, there is the inventiondescribed in the Japanese Patent Application Laid-open No. Hei 6-300869.In this prior art, a distance between various kinds of electronic partsand a magnetic sensor that is sufficient to eliminate influence of theelectronic parts is studied in detail, and the position of the magneticsensor is determined based on the study.

[0010] That is, the magnetic sensor is arranged as far as possible froman electronic part that is susceptible to magnetization to make theinfluence of the electronic part to the magnetic sensor minimum.

PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] However, the invention described in the Japanese PatentApplication Laid-open No. Hei 6-300869 has a problem that, since amagnetic sensor is arranged apart from an electronic part that issusceptible to magnetization, the configuration of the magnetic sensoris considerably limited regarding a place where it is arranged, which isa substantial restriction in designing the product. Particularly, sincethere is a strong need for miniaturization of a portable electronicapparatus, this restriction in arrangement is a large problem from theviewpoint of securing freedom of designing including planning. Such arestriction in arrangement not only poses a problem of not being capableof adopting a novel form conforming to a fashion as an outward design(form), but also is a problem in an aspect of functionality.

[0012] That is, a size and form are a part of important functions initself in a portable electronic instrument. For example, in the case ofa portable electronic instrument, particularly a wristwatch, or abarometer, a pressure gauge and the like that are used in skydiving,skin diving or the like, a shape with a part carelessly protruding fromthe outer configuration or a too large shape is not only inconvenientfor handling, but also is an obstacle in an emergency operation, whicheven has a possibility of resulting in an unexpected accident.

[0013] Further, since it is necessary to secure a distance between apart that is susceptible to magnetization and a magnetic sensor, a frameand a substrate that support the part and the sensor inevitably take alarge shape. Thus, there is a problem that materials used in the frame,the substrate and the like increase in volume, which not only increasesmanufacturing costs but also increases packaging costs andtransportation costs.

SUMMARY OF THE INVENTION

[0014] Therefore, it is an object of the present invention to provide anelectronic instrument that uses a magnetic sensor and a circular orsubstantially circular component assuming magnetism, wherein it is notnecessary to arrange the magnetic sensor spaced apart from thecomponent. It is another object of the present invention to provide anelectronic instrument that uses a circular or substantially circularcomponent assuming magnetism in the vicinity of the circumferencethereof and a magnetic sensor during processing steps of makingmaterials and parts circular or substantially circular shape, wherein itis not necessary to arrange the magnetic sensor spaced apart from thecomponent.

[0015] In order to attain the above-mentioned objects, a first aspect ofthe present invention is an electronic instrument characterized bycomprising: a circular or substantially circular component that issusceptible to magnetization; a magnetic sensor to output a signalcorresponding to a direction of a magnetic field that is arranged in anarbitrary position in a distance within the area of approximately2^(−1/2) of the radius from the center of the circular or substantiallycircular component; and correcting circuit to correct the signaloutputted from the magnetic sensor in accordance with the relativeposition between the component and the magnetic sensor.

[0016] With this configuration, even if the magnetic sensor is locatedin the upper or lower side of the circular or substantially circularcomponent that is susceptible to magnetization, since the magneticsensor can be arranged in an arbitrary position as long as it is withina predetermined distance from the center of the component, freedom ofselecting a place where the magnetic sensor is arranged is expanded indesigning the electronic instrument, and miniaturization and the like ofan electronic instrument can be attained while maintaining highprecision.

[0017] An electronic instrument in accordance with a second aspect ofthe present invention is an electronic instrument having a magneticsensor, characterized by comprising: a circular or substantiallycircular component that is susceptible to magnetization; a magneticsensor to output a signal corresponding to a direction of a magneticfield that is arranged in an arbitrary position on a straight linepassing the center of the component such that the straight line and adetection axis of the magnetism coincide; and correcting circuit tocorrect the signal outputted from the magnetic sensor in accordance withthe relative position between the component and the magnetic sensor.

[0018] With this configuration, even if the magnetic sensor cannot bearranged in an arbitrary position within a predetermined distance fromthe center of the circular or substantially circular component that issusceptible to magnetization, since it is possible to arrange themagnetic sensor in an arbitrary position on a straight line passing thecenter of the component such that the straight line and a detection axisof the magnetism coincide, freedom of selecting a place where themagnetic sensor is arranged is expanded in designing the electronicinstrument, and miniaturization and the like of an electronic instrumentcan be attained while maintaining high precision.

[0019] An electronic instrument in accordance with the third aspect ofthe present invention is an electronic instrument having a magneticsensor, characterized by comprising: a circular or substantiallycircular component that is susceptible to magnetization; an X axismagnetic sensor for detecting a magnetic field component in an X axisdirection that is arranged in an arbitrary position in a distance withinthe area of approximately 2^(−1/2) of the radius from the center of thecomponent, or is arranged such that a detection axis of the magneticsensor overlaps an X axis passing through the center of the component inan arbitrary position on the X axis or on its extended line; a Y axismagnetic sensor for detecting a magnetic field component in a Y axisdirection that is arranged in an arbitrary position in a distance withinthe area of approximately 2^(−1/2) of the radius from the center of thecomponent, or is arranged such that a detection axis of the magneticsensor overlaps a Y axis passing through the center of the component andperpendicular to the X axis in an arbitrary position on the Y axis or onits extended line; and correcting circuit to correct the signalsoutputted from the X axis magnetic sensor and the Y axis magnetic sensorin accordance with the relative position between the component and the Xand Y magnetic axes.

[0020] With this configuration, since each of the X axis magnetic sensorand the Y axis magnetic sensor can be arranged in an arbitrary positionwithin a predetermined distance from the center of the circular orsubstantially circular component, or in an arbitrary position on astraight line passing the center of the component where the arbitraryline and a detection axis of the magnetism coincide, freedom ofdesigning can be further increased, and miniaturization and the like ofan electronic instrument can be attained while maintaining highprecision.

[0021] An electronic instrument in accordance with a fourth aspect ofthe present invention is an electronic instrument having a magneticsensor characterized in that the component that is susceptible tomagnetization is a battery made of 304 stainless steel. Recently, thereare many electronic parts such as a button battery that have the size ofthe above -mentioned battery, which in conjunction with thisconfiguration, makes it possible to make an electronic instrument usingsuch a battery higher in performance, miniaturized, and so forth.

[0022] An electronic instrument in accordance with a fifth aspect of thepresent invention is an electronic instrument having a magnetic sensor,characterized by comprising: a circular or substantially circularcomponent assuming magnetism in the vicinity of its circumference byprocessing; a magnetic sensor to output a signal corresponding to adirection of a magnetic field that is arranged in a position inside thevicinity of the circumference assuming magnetism of the circular orsubstantially circular component; and correcting circuit to correct thesignal outputted by the magnetic sensor in accordance with the relativeposition between the component and the magnetic sensor.

[0023] With this configuration, even if the magnetic sensor is arrangedin the upper and the lower side of the circular or substantiallycircular component assuming magnetism in the vicinity of itscircumference by processing, since the magnetic sensor can be arrangedin an arbitrary position as long as it is within a predetermineddistance from the center of the component, freedom of selecting a placewhere the magnetic sensor is arranged is expanded in designing theelectronic instrument, and miniaturization and the like of an electronicinstrument can be attained while maintaining high precision.

[0024] An electronic instrument in accordance with a sixth aspect of thepresent invention is an electronic instrument having a magnetic sensor,characterized by comprising: a circular or substantially circularcomponent assuming magnetism in the vicinity of its circumference byprocessing; a magnetic sensor to output a signal corresponding to adirection of a magnetic field that is arranged in an arbitrary positionon a straight line passing the center of the component such that thestraight line and a detection axis of magnetism coincide; and correctingcircuit to correct the signal outputted from the magnetic sensordepending on the relative position between the component and themagnetic sensor.

[0025] With this configuration, even if the magnetic sensor cannot bearranged in an arbitrary position within a predetermined distance fromthe center of the circular or substantially circular component assumingmagnetism in the vicinity of its circumference by processing, since themagnetic sensor can be arranged in an arbitrary position on an arbitrarystraight line passing through the center of the component such that thestraight line and an detection axis of magnetism coincide, freedom ofselecting a place where the magnetic sensor is arranged is expanded indesigning the electronic instrument, and miniaturization and the like ofan electronic instrument can be attained while maintaining highprecision.

[0026] An electronic instrument in accordance with a seventh aspect ofthe present invention is an electronic instrument having a magneticsensor, characterized by comprising: a circular or substantiallycircular component assuming magnetism in the vicinity of itscircumference by processing; an X axis magnetic sensor for detecting amagnetic field component in an X axis direction that is arranged in aposition inside the vicinity of the circumference assuming magnetism ofthe circular or substantially circular component, or is positioned suchthat a detection axis of the magnetic sensor overlaps an X axis passingthe center of the component in an arbitrary position on the X axis or onits extended line; a Y axis magnetic sensor for detecting a magneticcomponent in a Y axis direction that is arranged inside the vicinity ofthe circumference assuming magnetism of the circular or substantiallycircular component, or is arranged such that a detection axis of themagnetic sensor overlaps a Y axis passing the center of the componentand perpendicular to the X axis in an arbitrary position on the Y axisor on its extended line; and correcting circuit to correct the signalsoutputted from the X axis magnetic sensor and the Y axis magnetic sensorin accordance with the relative position between the magnetic sensor andthe X axis and the Y axis magnetic sensors.

[0027] With this configuration, since each of the X axis magnetic sensorand the Y axis magnetic sensor can be arranged in an arbitrary positionwithin a predetermined distance from the center of the circular orsubstantially circular component assuming magnetism in the vicinity ofits circumference by processing or in an arbitrary position on anarbitrary straight line passing the center of the component such thatthe straight line and an detection axis of magnetism coincide, freedomof designing can be further increased, and miniaturization of anelectronic instrument can be attained while maintaining high precision.

[0028] An electronic instrument in accordance with an eighth aspect ofthe present invention is an electronic instrument having a magneticsensor characterized in that the circular or substantially circularcomponent assuming magnetism in the vicinity of its circumference byprocessing is a battery made of 304 stainless steel.

[0029] With this configuration, in conjunction with existing manyelectronic parts such as a button battery that have the size of theabove-mentioned battery, an electronic instrument using such anelectronic part can be made higher in performance, further miniaturized,and so forth.

[0030] An electronic instrument in accordance with a ninth aspect of thepresent invention is an electronic instrument having a magnetic sensor,characterized in that the magnetic sensor, the Y axis magnetic sensor orthe X axis magnetic sensor consists of a two axis magnetic sensor thatis capable of measuring both the magnetic field components in the X axisdirection and in the Y axis direction perpendicular to the X axis.

[0031] With this configuration, since the two axes can be measured byone magnetic sensor, an electronic instrument can be made higher inperformance, more miniaturized, and so forth.

[0032] An electronic instrument in accordance with a tenth aspect of thepresent invention is characterized in that the electronic instrument isan electronic azimuth indicator, a wristwatch with an electronic azimuthindicator, a pressure gauge with an electronic azimuth indicator, a carnavigation terminal apparatus, a portable electronic instrument with anelectronic azimuth indicator, or an electronic instrument with anelectronic azimuth indicator.

[0033] With this configuration, freedom of designing many electronicinstruments such as the above-mentioned ones having magnetic sensors canbe increased, and miniaturization and higher performance of theelectronic instruments are made possible.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] A preferred form of the present invention is illustrated in theaccompanying drawings in which:

[0035]FIG. 1 is an equivalent circuit diagram for illustrating afunction of a general magnetic sensor to be used in an electronicinstrument;

[0036]FIG. 2 is an illustration for showing the relationship between adetection signal of a magnetic sensor and a direction of a magneticfield when the magnetic sensor is caused to make a complete turn in aneven magnetic field;

[0037]FIG. 3 is a graph showing the relationship between a magneticfield component and a detection voltage Vby when a magnetic sensor iscaused to make a complete turn in a magnetic field;

[0038]FIG. 4 is an illustration for showing an outer configuration, asize, and a direction of a detection axis of a magnetic sensor used indata measurement for the present invention;

[0039]FIG. 5 is an illustration showing an outer configuration ofbatteries used in an experiment, and a data measuring position and acoordinate, as well as measurement results by a magnetic sensor;

[0040]FIG. 6 is a graph plotting actual detection data of a Y axismagnetic sensor in an even magnetic field and in a coordinate D of FIG.5: Y=−1.0,X=−1.0 of FIG. 5;

[0041]FIG. 7 is a graph plotting actual detection data of the Y axismagnetic sensor in coordinates E, F, G and H in FIG. 5;

[0042]FIG. 8 is an exploded perspective view showing an electronicazimuth indicator in accordance with an embodiment of the presentinvention;

[0043]FIG. 9 is a functional block diagram showing an electricconfiguration of an electronic azimuth indicator 10 in accordance withan embodiment of the present invention;

[0044]FIG. 10 is a circuit diagram showing more detailed embodiment of aY axis magnetic sensor 56, a X axis magnetic sensor 55, a sensor drivingcircuit 4, a the selection circuit 3 of FIG. 4.

[0045] FIGS. 11 are diagrams each showing a display example of anelectronic azimuth indicator in accordance with an embodiment of thepresent invention.

[0046] FIGS. 12 are diagrams showing embodiments for showing in detailarranged places of magnetic sensors X and Y in accordance with thepresent invention.

[0047] FIGS. 13 are illustrations showing examples of magnetismexhibited in the vicinity of the circumference of 304 stainless steeland the like by die cutting or part molding for forming the stainlesssteel and the like into a circular shape, and an arrangement of anmagnetic sensor for this purpose;

[0048]FIG. 14 is a diagram showing a state of a magnetic field in whicha spherical magnetic body is arranged in an even magnetic field; and

[0049]FIG. 15 is an illustration explaining magnetism generated byelongation when 304 stainless steel and the like is subjected to diecutting or bending.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0050] An embodiment of the present invention will now be described withreference to the drawings.

[0051] An equivalent circuit of a general one axis magnetic sensor isshown in FIG. 1. A magnetic sensor 1 is for outputting an electricsignal corresponding to a deflection e with respect to a direction of amagnetic field as a voltage difference between an output signals SYL andSYH. The difference of the output voltage is amplified and converted toa digital signal by a differential amplifier (not shown) and an A/Dconverter.

[0052] A relationship between a direction of a magnetic field and adetection signal of a magnetic sensor will now be described. FIG. 2 is adiagram illustrating the relationship between a detection signal of amagnetic sensor and a magnetic field in an even magnetic field. In FIG.2, (1) through (6) show a magnetic component By of the Y axis anddetection voltage Vby of the Y axis sensor in the respective directionswhen the magnetic sensor makes completely turn in the even magneticfield, (b) shows directions of the even magnetic field with respect tothe magnetic sensor, and (a) shows the relationship between the magneticfield component By in the Y axis direction and the detection voltage Vbyof the Y axis sensor.

[0053] (1) in FIG. 2 shows a case in which the X axis of the magneticsensor and the magnetic field are in the same direction. Then, as can beseen from (a), since the magnetic component By of the Y axis directionis “0”, the detection voltage Vby is also “0”. (2) in FIG. 2 shows acase in which the magnetic sensor and the magnetic field shift 45°toward the Y axis. (3) shows a state in which the direction of themagnetic field is the same as the Y axis direction. The detectionvoltage Vby gradually increases as the magnetic sensor turns around from(1) to (3), and when the magnetic field is in the same direction as theY axis ((3) in FIG. 2), the voltage reaches its largest value. Themagnetic sensor is further turned around thereafter, the detectionvoltage Vby drops to “0” again in a state (4) in which the magneticfield and the magnetic sensor are in the opposite directions.Thereafter, the detection voltage reaches its largest value in theopposite direction when the Y axis of the sensor and the magnetic fieldare in the opposite directions (5), and then returns to the state in theoriginal position (6).

[0054] As the above description have made clear, the relationshipbetween the detection voltage Vb detected by the magnetic sensor and thedirection of the magnetic field By shows a linear relation as shown bydotted lines in (b) of (1) through (6) in FIG. 2. Therefore, it ispossible to calculate a correct orientation from the voltage Vby thatare in a detected output. However, when something that is easilymagnetized is placed in the even magnetic field, since the magneticfield is affected and changes its direction near a magnetic body asdescribed above, it has been considered difficult to detect a correctorientation when a magnetic sensor is placed near a magnetic body.

[0055] This point will now be described with reference to FIG. 3. FIG. 3is a graph showing the relationship between the magnetic field componentBy and the detection voltage Vby when the magnetic sensor is caused tomake a complete turn in the magnetic field as in FIG. 2. In order tomake description to be easily understood, a case in which nothing isplaced in an even magnetic field and a case in which an article that issusceptible to magnetization is placed in the even magnetic field are isshown schematically.

[0056] In FIG. 3, a line a indicates an output of the magnetic sensorwhen the magnetic sensor is placed in the even magnetic field and iscaused to made a complete turn in the place, and a line b indicates anexample of a case in which an article that is susceptible tomagnetization is placed in the even magnetic field and the magneticsensor is placed in the vicinity thereof to make measurement in theplace. A line c indicates an example of a case in which an article thatis susceptible to magnetization is placed in the even magnetic field andmeasurement is made in another place near the article.

[0057] As shown by the line a on the graph of FIG. 3, in the evenmagnetic field, the detection voltage (Vby) of the magnetic sensor isproportional to the magnetic field direction (By), and varies linearlypassing the origin O. On the other hand, on the line b indicating a casein which an article that is susceptible to magnetization is placed nearthe magnetic sensor, the detection voltage (Vby) of the magnetic sensordoes not indicate a linear proportional relationship with respect to thechange of the magnetic field direction (By), and deflection G is causedin the detection voltage (Vby) by the magnetic field direction (By). Insuch a case, detection of an accurate orientation is difficult.

[0058] The line c in FIG. 3 indicates a case in which an article that issusceptible to magnetization is placed near the magnetic sensor, but themagnetic sensor is arranged in a predetermined position. It is foundthat, even if an article that is susceptible to magnetization is placednear the magnetic sensor, the relation between the detection voltage(Vby) of the magnetic sensor and the magnetic field direction (By) haslinearity by arranging the magnetic sensor in a predetermined position.However, inclination of the straight line is different from that in thecase of an even magnetic field, and the line does not pass the-origin Pand is spaced apart from the origin by “H”. Therefore, since therelationship has linearity, accurate measurement of orientation ispossible if the inclination and the “H” are corrected.

[0059] In addition, although not shown in the figure, the distance “H”from the origin O and inclination of the straight line respectively varydepending on a measurement position of the magnetic sensor. Detailsthereof will be described later.

[0060] Under the above-mentioned prerequisite, the inventors of thispatent application measured and analyzed data using a button typebattery (model number CR2025) manufactured by Matsushita Denchi KogyoKabushiki Kaisha and a button type battery (model number CR1616)manufactured by Kabushiki Kaisha Sony Energy Tech in order to findmutual relationship among the direction of a magnetic field, theposition of a part that is susceptible to magnetization and the positionof a magnetic sensor. As a result, it was found that a position existswhere a detection voltage (Vby) of the magnetic sensor varies linearly(hereinafter referred to as “has linearity”) in accordance with adirection of a magnetic field (By) even in the vicinity of the battery.This indicates that it is possible to arrange the magnetic sensor andthe battery in proximity to each other unlike the above-mentioned priorart.

[0061] Description will be made with reference to FIGS. 4 through 7.FIG. 4 is a magnetic sensor of a magnetic resistance type used for thedata measurement in this experiment. The size of the magnetic sensor isapproximately 1.2 mm long, approximately 0.6 mm wide, and approximately0.4 mm thick, which is extremely small. In addition, a detection axis ofmagnetism is in a longitudinal direction of the magnetic sensor.Further, the magnetic sensor is similar to a magnetic sensor describedin the U.S. Pat. No. 5,521,501.

[0062] In FIG. 4, reference numeral 55 denotes an X axis magnetic sensorfor detecting a magnetic field component in the X axis direction, andreference numeral 56 denotes a Y axis magnetic sensor for detecting amagnetic field component in the Y axis direction. The X axis magneticsensor 55 and the Y axis magnetic sensor 56 are implemented on a printedsubstrate such that the detection axes are perpendicular each other.

[0063]FIG. 5 shows the outer configuration of the above-mentionedbatteries manufactured by Matsushita Denchi Kogyo Kabushiki Kaisha andKabushiki Kaisha Sony Energy Tech, and a data measuring position and acoordinate of the above-mentioned magnetic sensor. FIG. 5 shows the Xaxis magnetic sensor 55 and the Y axis magnetic sensor 56 when thecenter of the battery is set in the center of the coordinate axes, thecoordinates are divided into a lattice shape with a predetermineddistance interval, and the magnetic sensors are arranged such that thepoint of intersection of the detection axes coincide with the lattice.

[0064] Then, as a result of the measurement at each lattice point, if itis recognized that there is linearity between variation of a magneticfield direction (By) and a detection output (Vby), the X axis magneticsensor 55 or the Y axis magnetic sensor 56 is circled, and, if not, theX axis magnetic sensor 55 or the Y axis magnetic sensor 56 is crossedout. Further, the battery used in this experiment has a thin cylindricalshape of CR2025, and has a structure covered by the 304 stainless steel.A diameter L and a lattice interval A of the battery are L=20 mm, A=5 mmin the case of CR2025, and L=16 mm, A=4 mm in the case of CR1616.

[0065] Description will now be made using actual detection data. FIG. 6is a graph plotting actual detection data of the Y axis magnetic sensorin the even magnetic field and in the coordinate D in FIG. 5: Y=−1.0,X=−1.0 (unit: cm) when the battery CR2025 is used, where a line aindicates detection data in the even magnetic field and a line dindicates detection data in the coordinate D. As can be seen from FIG.6, the line a indicating detection outputs in the even magnetic fieldshows linearity passing the origin O, and detection outputs measurednear the battery form the line d in an oval shape, which does not havelinearity.

[0066]FIG. 7 is a graph plotting detection data of the Y axis magneticsensor in the coordinates E, F and G in FIG. 5 when the battery CR2025is used. A line e in an oval shape shows detection data of the Y axismagnetic sensor in the coordinate E: Y=−1.0, X=−0.5, and it will be seenthat the line does not have linearity as in the case of the coordinateD. A line f plots detection data of the Y axis magnetic sensor in thecoordinate F: Y=−0.5, X=−0.5, and it will be seen that, although theline does not pass the origin O, output of the magnetic sensor varieslinearly in accordance with the direction of the magnetic field. Lines gand h plot detection data of the Y axis magnetic sensor in thecoordinates G: Y=0, X=−0.5 and H: Y=−1.0, X=0. As in the case of theline f, it will be seen that, although the lines do not pass the originO, output of the magnetic sensor varies linearly in accordance with thedirection of the magnetic field.

[0067] Therefore, linearity can be acquired if the sensor is arranged ina predetermined area from the center, or even if the sensor is notarranged in a predetermined area, linearity can be acquired when it isarranged on the Y axis. Further, although not illustrated, the X axismagnetic sensor has results similar to the above.

[0068]FIG. 5 shows whether or not linearity can be acquired in detectionresults for each measurement position. In FIG. 5, detection outputs ofthe X axis magnetic sensor and the Y axis magnetic sensor are measuredfor each coordinate position shown in the figure as described above, andmeasurement results are shown for each coordinate position. Throughthese measurements as well as collection and analysis of data, thefollowing facts have been found. As to be seen from FIG. 7, if the Yaxis magnetic sensor is arranged in a distance within approximately2^(−1/2) of the radius R from the center of a battery 20, detectionoutput (Vby) has linearity whichever position the sensor is located.FIG. 7 shows the detection output of the Y axis magnetic sensor, whiledetection outputs (Vbx) of the X axis magnetic sensor also has linearityas shown in FIG. 5. In addition, although FIG. 7 shows detection data ofa battery with the diameter of 20 mm, batteries with different diametersshow similar characteristics. In a battery with the diameter of 16 mmmanufactured by Kabushiki Kaisha Sony Energy Tech, detection data in thecoordinate X=−0.4, Y=−0.4 (unit: cm) shows that the magnetic sensoroutput (Vby) varies linearly in accordance with change in the directionof the magnetic field (By) similar to the data of the coordinate F inFIG. 7.

[0069] In addition, distribution of determinations on the presence orabsence of linearity for each coordinate position in the battery withthe diameter of 16 mm has the same results as the battery with thediameter of 20 mm. However, in this case, the measurement positioninterval A shown in FIG. 5 is A=0.4 cm.

[0070] Further, it has been found that, even if the X axis magneticsensor X or the Y axis magnetic sensor Y is arranged in a positionexceeding approximately 2^(−1/2) of the radius R, when the detectionaxes (XA, YA) of these sensors are arranged such that the axes overlapan axis passing the center O of the battery 20, linearity is acquiredbetween change in the direction of the magnetic field and the detectionoutput. In this way, if linearity is acquired between the change in thedirection of the magnetic field and the detection output, even if thedetection axes are shifted from the origin O or the inclination isdifferent, an accurate orientation can be calculated by correcting thesedeflections.

[0071] An embodiment of the present invention will now be described withreference to FIG. 8. FIG. 8 is an exploded perspective view showing aphysical structure of an electronic azimuth indicator in accordance withthe embodiment of the present invention. FIG. 8 shows only partsnecessary for describing the present invention, and smaller parts suchas a control unit are omitted. Basically, the electronic azimuthindicator is composed of a battery 51, two magnetic sensors 55 and 56for detecting magnetic field components of the X axis and the Y axis,and a liquid crystal panel 58 that is a display unit.

[0072] The button type battery 51 with a metal such as 304 stainlesssteel covering its exterior is mounted on a circuit substrate 54 via abattery plus terminal 52 and a frame A while being pressed by a batterycover 50. The battery plus terminal 52 is fixed to the circuit substrate54 by lock screws 60. A battery minus terminal 59 is provided on thecircuit substrate 54 such that the battery minus terminal 59 ispressingly brought into contact with the minus terminal portion of thebattery 51 when the battery 51 is mounted.

[0073] On the circuit substrate 54, the X axis magnetic sensor 55 fordetecting magnetic field component in the X axis direction and the Yaxis magnetic sensor 56 for detecting magnetic field component in the Yaxis direction are provided in positions close to the center of thebattery 51. A frame B is provided under the circuit substrate 54, andthe liquid crystal panel 58 is fixed under the frame B. The liquidcrystal panel 58 consists of a liquid crystal and a pair of sheets, atleast one of which is transparent, for sealing the liquid crystaltherebetween. In the liquid crystal panel a plurality of liquid crystalpixels are arranged in a matrix-line manner, and each pixel is driven byan electronic signal. The liquid crystal panel 58 is electricallyconnected to the circuit substrate by a pair of connectors 57 andperforms displaying based on a control signal from a control unit (notshown). Further, the liquid crystal panel 58 may be the one in which allthe contents that should be displayed are arranged segmentally inadvance using segments.

[0074] In this embodiment, miniaturization of the electronic azimuthindicator is attained by providing the magnetic sensors 55 and 56 closeto the center of the battery 51. In this way, as described above, sinceoutputs of the magnetic sensors 55 and 56 have linearity with respect tothe direction of the magnetic field as long as the magnetic sensors 55and 56 are arranged in arbitrary positions within an area in apredetermined distance from the center of the battery 51, or on the Xaxis passing the center of the battery or on the Y axis perpendicular tothe X axis, even if the magnetic sensors are in the lower or the uppersides of the battery 51, the accuracy in the orientation detection isnot be deteriorated. Therefore, the magnetic sensors can be arranged inarbitrary positions within the above-mentioned area according tonecessities of planning or designing, and miniaturization, improvementof design, and reduction of costs can be attained.

[0075]FIG. 9 is a functional block diagram showing an electricconfiguration of an electronic azimuth indicator 10 in accordance withan embodiment of the present invention. For ease of understanding,parts-that are functionally identical with those in FIG. 8 are denotedby the same numbers. As in FIG. 8, a Y axis magnetic sensor 56 is amagnetic sensor for detecting magnetic field component in the Y axisdirection, and an X axis magnetic sensor 55 is a magnetic sensor fordetecting magnetic field component in the X axis direction, which detectdeflection amounts of the X axis and the Y axis with respect to thegeomagnetism as electric signals and output them.

[0076] A sensor driving circuit 4 provides driving power to the magneticsensors 55 and 56. A selection circuit 3 selects the magnetic sensor 55or 56 that should detect a signal in accordance with control signals ENYand ENX from a control circuit 8. A detection signal from the magneticsensor 55 or 56 selected by the selection circuit 3 is converted to adigital signal from an analog signal by an A/D converting circuit 5.

[0077] A correcting circuit 6 corrects an output signal from the A/Dconverting circuit 5 in accordance with installed places orcharacteristics of the magnetic sensors 55 and 56. As shown in the linec of FIG. 3, although a detection output having linearity with respectto changes in the direction of the magnetic field can be acquired fromthe magnetic sensors 55 and 56 arranged in a predetermined position neara battery 51, an output value is deflected by “H” from the origin O inaccordance with the arranged places of the magnetic sensors unlike thecase in which the magnetic sensors are arranged in the even magneticfield. Therefore, an accurate orientation is calculated by correcting,using the correcting circuit 6, the deflection due to the arrangedplaces of the magnetic sensors, bias due to characteristics and the likeheld by each magnetic sensor, as well as shift (declination) of themagnetic north and the north on the map.

[0078] An orientation display signal corrected by the correcting circuit6 is supplied to a displaying circuit 7, and is displayed by thedisplaying circuit 7 under the control of a controlling circuit 8. Here,as is evident to those having ordinary skills in the art, thecontrolling circuit 8 and the correcting circuit 6 may respectively becomposed of a microprocessor and an RAM, an ROM and the like storingtherein a predetermined program or data.

[0079] More detailed embodiment of the Y axis magnetic sensor 56, the Xaxis magnetic sensor 55, the sensor driving circuit 4, and the selectioncircuit 3 of FIG. 9 is shown in FIG. 10. Either of the magnetic sensor55 or 56 is selected by the control signal ENX or ENY from thecontrolling circuit 8, and electric power is supplied to the selectedmagnetic sensor 55 or 56 from the sensor driving circuit 4.

[0080] ENY and ENX are not in the active state (are not “H”)simultaneously. When ENY is “H”, a transistor 11 is in the on state, anddriving electric power is supplied to the Y axis magnetic sensor 56.Since switching gates 13 and 14 are open and gates 15 and 16 are closed,output signals SYH and SYL from the Y axis magnetic sensor 56 are sentto the A/D converting circuit 5. Since the gates 15 and 16 are closedthen, the output signals SYH and SYL are differential amplified by theA/D converting circuit 5 and, at the same time, are outputted as digitalsignals corresponding to volumes of the output signals.

[0081] Similarly, ENX is a signal for selecting the X axis magneticsensor 55 which supplies electric power to the X axis magnetic sensor 55by turning on a transistor 12 and, at the same time, sends outputs SXHand SXL of the X axis magnetic sensor 55 to the A/D converting circuit 5by opening the switching gates 15 and 16.

[0082] As shown in FIG. 9, the output signals SXH, SXL, SYH and SYL areanalog/digital converted in the A/D converting circuit 5, and aredisplayed by the displaying circuit 7 via the correcting circuit 6.

[0083] Examples of a case in which display is made by an electronicazimuth indicator 70 are shown in FIGS. 11. For example, if theelectronic azimuth indicator 70 is directed to the north, a directionindication mark 71 represented by a bold arrow, an orientation 72represented as N, and a bias angle 73 from the north are shown in FIG.11A. In this case, since the orientation is “N”, that is the north, andthe bias is “0”, the figure indicates that the direction of thedirection indication mark 71 is the north (more strictly, the magneticnorth). In FIG. 11B, since the orientation 72 is “NE”, that is thenortheast, and the angle 73 from the north is “45”, the figure indicatesthat the direction of the direction indication mark 71 is in theorientation 450 from the north. Similarly, FIG. 11C indicates that thedirection of the direction indication mark 71 is the east, which is inthe orientation 900 from the north. Although display form such as theabove is shown here, those having ordinary skills in the art can freelyselect a display form, a display method, a display medium and the like,for example, an LED may be lit instead of the arrow of the directionindication mark 71.

[0084] Arrangement of the magnetic sensor will now be described more indetail with reference to FIG. 12. FIG. 12 show embodiments fordescribing in detail arranged places of magnetic sensors 55 and 56 inaccordance with the present invention. A component in a circular shapehaving magnetism (for example, a battery consisting of a frame of 304stainless steel) 21, the X axis magnetic sensor 55 and the Y axismagnetic sensor 56 respectively provided in an electronic instrument 30are shown in FIG. 12 A through FIG. 12E. FIG. 12A and FIG. 12B of areexamples in which the X axis magnetic sensor 55 and the Y axis magneticsensor 56 are arranged in a distance within 2^(−1/2) of the radius Rfrom the center O of a component 21. The sensors can be arranged inarbitrary positions as long as the positions are within the area.Detection axis orientations of the sensors do not need to be on an axispassing the center O of the component. The X axis magnetic sensor 55 andthe Y axis magnetic sensor 56 are arranged such that their detectionangles are perpendicular to each other.

[0085]FIG. 12C shows an example of a case in which the X axis magneticsensor 55 and the Y axis magnetic sensor 56 are arranged outside2^(−1/2) of the radius R of the component 21 and in the vicinity of thecircumference of the component 21. In this case, the magnetic sensor 55or 56 must be arranged on an X axis or a Y axis passing the center O ofthe component 21 such that the detection axes of the magnetic sensors 55and 56 overlap the X axis and the Y axis.

[0086]FIG. 12D is an example in which only the Y axis magnetic sensor 56is arranged outside the component 21 in FIG. 12C. In this case as well,the Y axis magnetic sensor 56 must be arranged on the Y axis such thatits detection axis overlaps the Y axis passing the center of thecomponent 21. In FIG. 12E, the X axis magnetic sensor 55 is arranged ina position slightly outside the circumference of the component 21, andthe Y axis magnetic sensor 56 is provided in a position within 2^(−1/2)of the radius R from the center of the component 21. In this case,although the X axis magnetic sensor 55 must be on the X axis passing thecenter O of the component 21 as in FIG. 12C and FIG. 12D, the Y axismagnetic sensor 56 can be provided in an arbitrary position within2^(−1/2) of the radius R.

[0087] FIGS. 13 show arrangements of the X axis magnetic sensor 55 andthe Y axis magnetic sensor 56 in a case in which a place assumingmagnetism varies depending upon stress applied by bending or die cuttingand materials. For example, if a place assuming magnetism is limited toa considerably small vicinity of the circumference S, the magneticsensors 55 and 56 can be arranged within an area not affected by themagnetism (within the area of the radius Z) (see FIG. 13A). To thecontrary, as shown in FIG. 13B, if a place assuming magnetism by suchprocessing and the like extends from a large circumference to an area ofa distance W, the arranged places of the magnetic sensors 55 and 56 arelimited to a small area not affected by the magnetism (an area of theradius Z). However, in a case in which the sensors are arranged on axespassing the center O of the components 22 and 23, arrangement is thesame as described in FIG. 12.

[0088] Although the magnetic sensor described above has one detectionaxis, the same is true for a magnetic sensor having two detection axesof an X axis and a Y axis.

[0089] As described above, the present invention has bee devised basedon the knowledge from various kinds of analysis data that, when adirection of magnetism changes, a detection output of a magnetic sensorhas relationship with a direction of magnetism to change linearly inaccordance with the change in direction of magnetism (linearity) as longas the magnetic sensor is within the above-mentioned area even if it isplaced in the lower side or the upper side of a substance that issusceptible to magnetization. Although reasons why such a characteristicis shown are not accurately and theoretically solved at the presenttime, it is considered that such a characteristic might be expressed dueto stress when a part made of a material such as 304 stainless steel isbent or die cut in a circular shape. At present, since many buttonbatteries are used as a power source of a compact electronic instrument,and most of such button batteries use 304 stainless steel, it isextremely beneficial if a magnetic sensor can be arranged in the upperside or the lower side of such a button battery.

[0090] The present invention is applicable if a magnetic sensor is usedtogether with a circular or substantially circular component that issusceptible to magnetization. Therefore, the present invention can be,embodied not only in an electronic azimuth indicator, but also in anyelectronic instruments including a magnetic sensor, such as anelectronic wristwatch, a pressure gauge, a barometer, a car navigationterminal apparatus or an electronic notebook, all having an azimuthindicator, and therefore the present invention is applied to all ofthese electronic instruments.

[0091] As described above, since the present invention enables toarrange a magnetic sensor above or below of a circular part that issusceptible to magnetization or in its vicinity while maintaining theability of the magnetic sensor at high in precision, whereasconventionally a magnetic sensor is spaced apart from a part that issusceptible to magnetization, freedom in designing an electronicinstrument is considerably increased, and not only miniaturization of anelectronic instrument is made possible but also freedom in relation toforms such as a design can be increased. In addition, according to thepresent invention, a compact and high-precision electronic azimuthindicator, an electronic instrument having such an azimuth indicator, ora portable electronic instrument having such an azimuth indicator can beprovided.

[0092] According to the first aspect of the present invention, since amagnetic sensor is arranged in an arbitrary position in a distancewithin approximately 2^(−1/2) of the radius from the center of acircular or substantially circular component that is susceptible tomagnetization, the magnetic sensor can be arranged in an arbitraryposition as long as it is within a predetermined distance from thecenter even if it is placed in the upper side or the lower side of thecircular or substantially circular component that is susceptible tomagnetization. Therefore, the magnetic sensor and the component in acircular shape or the like that is susceptible to magnetization can bearranged in a position where the two overlap in a proximatecross-sectional direction. In addition, since freedom of selecting aplace to arrange a magnetic sensor is expanded in designing anelectronic instrument, the electronic instrument can be miniaturizedwhile maintaining high-precision.

[0093] According to the second aspect of the present invention, since amagnetic sensor to output a signal corresponding to a direction of amagnetic field is arranged in an arbitrary position on an arbitrarystraight line passing the center of a circular or substantially circularcomponent that is susceptible to magnetization such that the straightline and a detection axis of magnetism coincide, even if the magneticsensor cannot be arranged in an arbitrary position within apredetermined distance from the center of the circular or substantiallycircular component that is susceptible to magnetization, it can bearranged in an arbitrary position on an arbitrary straight line passingthe center of the component such that the straight line and a detectionaxis of magnetism coincide. In addition, a magnetic sensor can bearranged two-dimensionally in the vicinity of a component in a circularshape or the like without overlapping each other. In addition, freedomof designing a place to arrange a magnetic sensor is expanded indesigning an electronic instrument, and it is made possible tominiaturize the electronic instrument while maintaining high-precision.

[0094] According to the third aspect of the present invention, byarranging an X axis magnetic sensor in a position within a predetermineddistance from a circular or substantially circular component that issusceptible to magnetization, or in an arbitrary position on an X axispassing the center of the component or its extended line, and arranginga Y axis magnetic sensor in a position within a predetermined distancefrom the component in a circular or substantially circular shape that issusceptible to magnetization, or in an arbitrary position on a Y axisperpendicular to the X axis of the component or its extended line, evenif the X axis magnetic sensor and the Y axis magnetic sensor are used,each of the magnetic sensors can be arranged in a considerably freeposition with respect to the component. In addition, freedom ofdesigning can be further increased, and miniaturization and the like canbe possible while maintaining high precision.

[0095] According to the fourth aspect of the present invention, since acomponent that is susceptible to magnetization is a battery made of 304stainless steel, it can be detected without being affected by a buttonbattery and the like. Further, since a magnetic sensor does not need tobe spaced apart from the battery, an electronic instrument can be madehigher in performance and miniaturized, and so forth.

[0096] According to the fifth aspect of the present invention, byarranging a magnetic sensor in a position inside the vicinity of thecircumference assuming magnetism of a circular or substantially circularcomponent assuming magnetism in the vicinity of its circumferenceassuming magnetism by processing, the magnetic sensor can be arranged inan arbitrary position in a predetermined distance from the center of thecomponent in a circular shape, and can be miniaturized while maintaininghigh precision.

[0097] According to the sixth aspect of the present invention, since amagnetic sensor is arranged in an arbitrary position on an arbitrarystraight line passing the center of a circular or substantially circularcomponent assuming magnetism in the vicinity of its circumference byprocessing such that the straight line and a detection axis of magnetismcoincide, even if the magnetic sensor is placed in the upper side or thelower side of the circular or substantially circular component assumingmagnetism in the vicinity of its circumference by processing, or themagnetic sensor cannot be arranged in an arbitrary position within apredetermined distance from the center, it can be arranged in anarbitrary position on an arbitrary straight line passing the center ofthe component such that the straight line and a detection axis ofmagnetism coincide. In this way, freedom of selecting a place forarranging a magnetic sensor is expanded in designing an electronicinstrument, and miniaturization and the like of the magnetic sensor ismade possible while maintaining high precision.

[0098] According to the seventh aspect of the present invention, byarranging an X axis magnetic sensor in a position within a predetermineddistance from a circular or substantially circular component assumingmagnetism in the vicinity of its circumference by processing, or in anarbitrary position on an X axis passing the center of the component orits extended line, and arranging a Y axis magnetic sensor in a positionwithin a predetermined distance from the component in a circular ofsubstantially circular shape assuming magnetism in the vicinity of itscircumference by processing, or in an arbitrary position on a Y axisperpendicular to the X axis of the component or its extended line, evenif the X axis magnetic sensor and the Y axis magnetic sensor are used,each of the magnetic sensors can be arranged in a considerably freeposition with respect to the component. In this way, the magnetic sensorcan be arranged in a predetermined position near the component in acircular shape. In addition, freedom of designing can be furtherincreased, and miniaturization and the like are made possible whilemaintaining high precision.

[0099] According to the eighth aspect of the present invention, since acircular or substantially circular component assuming magnetism in thevicinity of its circumference by processing is a battery made of 304stainless steel, it is not affected by a button battery and the like.Further, an electronic instrument using such a buttery and the like canbe made higher in performance, more miniaturized, and so forth.

[0100] According to the ninth aspect of the present invention, since amagnetic sensor, a Y axis magnetic sensor or a X axis magnetic sensor isthe one consisting of a two axis magnetic sensor that is capable ofmeasuring both magnetic field components of a X axis direction and a Yaxis direction perpendicular to the X axis, an electronic instrumentusing such a battery and the like can be made higher in performance,more miniaturized, and so forth.

[0101] According to the tenth aspect of the present invention, by makingan electronic instrument an electronic azimuth indicator, an electronicwristwatch with an electronic azimuth indicator, a pressure gauge withan electronic azimuth indicator, a car navigation terminal apparatuswith an electronic azimuth indicator, a portable electronic instrumentwith an electronic azimuth indicator, or an electronic instrument withan electronic azimuth indicator, freedom to design all of theseelectronic instrument having a magnetic sensor can be increased, and theelectronic instrument can be more miniaturized and made higher inperformance.

What is claimed is:
 1. An electronic instrument having a magnetic sensorcomprising: a circular or substantially circular component that issusceptible to magnetization; a magnetic sensor to output a signalcorresponding to a direction of a magnetic field that is arranged in anarbitrary position in a distance within the area of approximately2^(−1/2) of the radius from the center of said circular or substantiallycircular component; and a correcting circuit to correct the signaloutputted from said magnetic sensor in accordance with the relativeposition between said component and said magnetic sensor.
 2. Anelectronic instrument having a magnetic sensor comprising: a circular orsubstantially circular component that is susceptible to magnetization; amagnetic sensor to output a signal corresponding to a direction of amagnetic field that is arranged in an arbitrary position on a straightline passing the center of said component such that said straight lineand a detection axis of magnetism coincide; and a correcting circuit tocorrect the signal outputted from said magnetic sensor in accordancewith the relative position between said component and said magneticsensor.
 3. An electronic instrument having a magnetic sensor comprising:a circular or substantially circular component that is susceptible tomagnetization; an X axis magnetic sensor to detect a magnetic fieldcomponent in an X axis direction that is arranged in an arbitraryposition in a distance within the area of approximately 2^(−1/2) of theradius from the center of said component, or is arranged such that adetection axis of said magnetic sensor overlaps an X axis passingthrough the center of said component in an arbitrary position on said Xaxis or on its extended line; a Y axis magnetic sensor to detect amagnetic field component in a Y axis direction that is arranged in anarbitrary position in a distance within the area of approximately2^(−1/2) of the radius from the center of said component, or is arrangedsuch that an detection axis of the magnetic sensor overlaps an Y axispassing through said component and perpendicular to said X axis in anarbitrary position on said Y axis or on its extended line; and acorrecting circuit to correct the signals outputted from said X axismagnetic sensor and said Y axis magnetic sensor in accordance with therelative position between said component and said X and Y magneticsensors.
 4. An electronic instrument having a magnetic sensor accordingto claim 1, wherein said component that is susceptible to magnetizationis a battery made of stainless steel.
 5. An electronic instrument havinga magnetic sensor according to claim 2, wherein said component that issusceptible to magnetization is a battery made of stainless steel.
 6. Anelectronic instrument having a magnetic sensor according to claim 3,wherein said component that is susceptible to magnetization is a batterymade of stainless steel.
 7. An electronic instrument having a magneticsensor comprising: a circular or substantially circular componentassuming magnetism in the vicinity of its circumference by processing; amagnetic sensor to output a signal corresponding to a direction of amagnetic field that is arranged in a position inside said vicinity ofthe circumference assuming magnetism of said circular or substantiallycircular component; and a correcting circuit to correct the signaloutputted by said magnetic sensor in accordance with the relativeposition between said component and said magnetic sensor.
 8. Anelectronic instrument having a magnetic sensor comprising: a circular orsubstantially circular component assuming magnetism in the vicinity ofits circumference by processing; a magnetic sensor to output a signalcorresponding to a direction of a magnetic field that is arranged in anarbitrary position on a straight line passing the center of saidcomponent such that said straight line and a detection axis of magnetismcoincide; and a correcting circuit to correct the signal outputted fromsaid magnetic sensor depending on the relative position between saidcomponent and said magnetic sensor.
 9. An electronic instrument having amagnetic sensor comprising: a circular or substantially circularcomponent assuming magnetism in the vicinity of its circumference byprocessing; an X axis magnetic sensor for detecting a magnetic fieldcomponent in the X axis direction that is arranged in a position insidesaid vicinity of the circumference assuming magnetism of said circularor substantially circular component, or is arranged such that adetection axis of said magnetic sensor overlaps an X axis passing thecenter of said component in an arbitrary position on the X axis or onits extended line; a Y axis magnetic sensor for detecting a magneticcomponent in a Y axis direction that is arranged inside said vicinity ofthe circumference assuming magnetism of said circular or substantiallycircular component, or is arranged such that a detection axis of saidmagnetic sensor overlaps a Y axis passing the center of said componentand perpendicular to said X axis in an arbitrary position on the Y axisor on its extended line; and a correcting circuit to correct the signalsoutputted from said X axis magnetic sensor and said Y axis magneticsensor.
 10. An electronic instrument having a magnetic sensor accordingto claim 7, wherein said circular or substantially circular component isa battery made of stainless steel.
 11. An electronic instrument having amagnetic sensor according to claim 8, wherein said circular orsubstantially circular component is a battery made of stainless steel.12. An electronic instrument having a magnetic sensor according to claim9, wherein said circular or substantially circular component is abattery made of stainless steel.
 13. An electronic instrument having amagnetic sensor according to claim 1, wherein said magnetic sensor, saidY axis magnetic sensor or said X axis magnetic sensor consists of a twoaxis magnetic sensor that is capable of measuring both the magneticfield components in said X axis direction and in said Y axis directionperpendicular to said X axis.
 14. An electronic instrument having amagnetic sensor according to claim 2, wherein said magnetic sensor, saidY axis magnetic sensor or said X axis magnetic sensor consists of a twoaxis magnetic sensor that is capable of measuring both the magneticfield components in said X axis direction and in said Y axis directionperpendicular to said X axis.
 15. An electronic instrument having amagnetic sensor according to claim 3, wherein said magnetic sensor, saidY axis magnetic sensor or said X axis magnetic sensor consists of a twoaxis magnetic sensor that -is capable of measuring both the magneticfield components in said X axis direction and in said Y axis directionperpendicular to said X axis.
 16. An electronic instrument having amagnetic sensor according to claim 7, wherein said magnetic sensor, saidY axis magnetic sensor or said X axis magnetic sensor consists of a twoaxis magnetic sensor that is capable of measuring both the magneticfield components in said X axis direction and in said Y axis directionperpendicular to said X axis.
 17. An electronic instrument having amagnetic sensor according to claim 8, wherein said magnetic sensor, saidY axis magnetic sensor or said X axis magnetic sensor consists of a twoaxis magnetic sensor that is capable of measuring both the magneticfield components in said X axis direction and in said Y axis directionperpendicular to said X axis.
 18. An electronic instrument having amagnetic sensor according to claim 9, wherein said magnetic sensor, saidY axis magnetic sensor or said X axis magnetic sensor consists of a twoaxis magnetic sensor that is capable of measuring both the magneticfield components in said X axis direction and in said Y axis directionperpendicular to said X axis.
 19. An electronic instrument having amagnetic sensor according to claim 1, wherein said electronic instrumentis an electronic azimuth indicator, a wristwatch with an electronicazimuth indicator, a pressure gauge with an electronic azimuthindicator, a car navigation terminal apparatus, a portable electronicinstrument with an electronic azimuth indicator, or an electronicinstrument with an electronic azimuth indicator.
 20. An electronicinstrument having a magnetic sensor according to claim 2, wherein saidelectronic instrument is an electronic azimuth indicator, a wristwatchwith an electronic azimuth indicator, a pressure gauge with anelectronic azimuth indicator, a car navigation terminal apparatus, aportable electronic instrument with an electronic azimuth indicator, oran electronic instrument with an electronic azimuth indicator.
 21. Anelectronic instrument having a magnetic sensor according to claim 3,wherein said electronic instrument is an electronic azimuth indicator, awristwatch with an electronic azimuth indicator, a pressure gauge withan electronic azimuth indicator, a car navigation terminal apparatus, aportable electronic instrument with an electronic azimuth indicator, oran electronic instrument with an electronic azimuth indicator.
 22. Anelectronic instrument having a magnetic sensor according to claim 7,wherein said electronic instrument is an electronic azimuth indicator, awristwatch with an electronic azimuth indicator, a pressure gauge withan electronic azimuth indicator, a car navigation terminal apparatus, aportable electronic instrument with an electronic azimuth indicator, oran electronic instrument with an electronic azimuth indicator.
 23. Anelectronic instrument having a magnetic sensor according to claim 8,wherein said electronic instrument is an electronic azimuth indicator, awristwatch with an electronic azimuth indicator, a pressure gauge withan electronic azimuth indicator, a car navigation terminal apparatus, aportable electronic instrument with an electronic azimuth indicator, oran electronic instrument with an electronic azimuth indicator.
 24. Anelectronic instrument having a magnetic sensor according to claim 9,wherein said electronic instrument is an electronic azimuth indicator, awristwatch with an electronic azimuth indicator, a pressure gauge withan electronic azimuth indicator, a car navigation terminal apparatus, aportable electronic instrument with an electronic azimuth indicator, oran electronic instrument with an electronic azimuth indicator.